Firms engaging in innovative practices have patents to prevent competitive forces from eroding the resulting economic rents; however, there is limited evidence regarding the impact of innovation on risk. We shed new light on how firms’ involvement in innovation activities impacts their volatility, particularly their idiosyncratic volatility. In this paper, we empirically examine the effect of innovation on idiosyncratic volatility. To do so, we empirically examine the impact of innovation, measured by patents weighted by citations and R&D expenditure, on the idiosyncratic volatility of firms. Using a large sample of 8256 US firms, we find that more innovation is associated with lower idiosyncratic volatility. We also find that information uncertainty is the channel through which innovation affects idiosyncratic risk. The results are robust for different measures of idiosyncratic volatility. These results have empirical implications for investors, managers, and firms engaging in innovation-related activities.

The purpose of this paper is to investigate the effect of the "limits of arbitrage" on securities mispricing. Specifically, I investigate the effect of the availability of substitutes and financial constraints on stock mispricing. . In addition, this study investigates the difference in the limits of arbitrage between stocks that are included in the Standard & Poor's 500 index (S&P 500 hereafter) and non-S&P 500 stocks. I expect S&P 500 stocks to have, on average, lower levels of the limits of arbitrage, in the sense that it will lead to lower mispricing for these stocks, relative to non-S&P 500 stocks. I also examine if the lower mispricing can be attributed to their lower limits of arbitrage.Modern finance theory and efficient market hypothesis suggest that security prices, at equilibrium, should reflect their fundamental value. If the market price deviates from the intrinsic value, then a risk-free profit opportunity has emerged and arbitrageurs will eliminate mispricing and equilibrium is restored. This arbitrage process is characterized by large number of arbitrageurs which have infinite access to capital. However, a better description of reality is that there are few numbers of arbitrageurs to the extent that they are highly specialized; and they have limited access to capital. Under these condition arbitrage is no more a risk-free activity and can be limited by several factors such as arbitrage risk and transaction costs.Other factors that are discussed in the literature are availability of substitutes and financial constraints. The former arises as a result of the specialization of arbitrageurs in the market in which they operate, while the latter arises as a result of the separation between arbitrageurs and capital.In this dissertation, I develop a measure of the availability of substitutes that is based on the propensity scores obtained from propensity score matching technique. In addition, I use the absolute value of skewness of returns as a proxy of financial constraints.Previous studies used the limits of arbitrage framework to explain pricing puzzles such as the closed-end fund discounts. However, closed-end fund discounts are highly affected by uncertainty of managerial ability and agency problems. This study overcomes this problem by studying the effect of limits of arbitrage on publicly traded securities. The results show that there is a significant relationship between proxies of limits of arbitrage and firm specific mispricing.More importantly, empirical results indicate that stocks that have no close substitutes have higher mispricing. In addition, stocks that have high skewness show higher mispricing.Subsequent studies show that the S&P 500 stocks have different levels of liquidity, analysts' coverage and volatility. These characteristics affect the ability of arbitrageurs to eliminate mispricing. Preliminary univariate tests show that S&P 500 stocks have, on average, lower mispricing and limits of arbitrage relative to non-S&P 500 stocks. In addition, the multivariate test shows that S&P 50...